Detecting and confining Sybil attack in wireless sensor networks based on reputation systems coupled with clustering algorithms
Posted on by araujo

Title: Detecting and confining Sybil attack in wireless sensor networks based on reputation systems coupled with clustering algorithms
Authors: Zorana Bankovic, David Fraga, José Manuel Moya, Juan Carlos Vallejo, Alvaro Araujo, Pedro Malagón, Juan Mariano de Goyeneche, Daniel Villanueva, Elena Romero and Javier Blesa
Published in: Journal Engineering Intelligent Systems, Vol 20, 3
ISSN : 1472-8915
Date of Publication: September 2010
Digital Object Identifier :
Web: http://www.crlpublishing.co.uk/journal.asp?j=eis&s=Recent%20Special%20Issues

The Sybil attack is one of the most aggressive and elusive attacks in sensor networks that can affect on many aspects of its operation. Thus, its efficient detection is of highest importance. In order to resolve this issue, in this work we propose to couple reputation systems with agents based on clustering algorithms trained for detecting outliers in data. The response of the system consists in assigning low reputation values to the compromised nodes rendering them isolated from the rest of the network. The main improvement of this work consists in the inclusion of distributed detector with redundancy, which provides optimal detector configuration in an autonomous way. Clustering algorithms deploy feature space based on sequences of sensor outputs. Our solution offers many benefits: scalable solution, fast response to adversarial activities, ability to detect unknown attacks, high adaptability and low consumption. The testing results demonstrate its high ability in detecting and confining Sybil attack.

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Bio-inspired enhancement of reputation systems for intelligent environments
Posted on by araujo

Title: Bio-inspired enhancement of reputation systems for intelligent environments
Authors:Zorana Bankovic, David Fraga, José Manuel Moya, Juan Carlos Vallejo, Pedro Malagón, Alvaro Araujo, Juan Mariano de Goyeneche, Elena Romero, Javier Blesa, Daniel Villanueva y Octavio Nieto-Taladriz
Published in: Information Sciences
ISSN : 0020-0255
Date of Publication: July 2011
Digital Object Identifier : 10.1016/j.ins.2011.07.032
Web: http://www.sciencedirect.com/science/article/pii/S0020025511003641

Providing security to the emerging field of ambient intelligence will be difficult if we rely only on existing techniques, given their dynamic and heterogeneous nature. Moreover, security demands of these systems are expected to grow, as many applications will require accurate context modeling. In this work we propose an enhancement to the reputation systems traditionally deployed for securing these systems. Different anomaly detectors are combined using the immunological paradigm to optimize reputation system performance in response to evolving security requirements. As an example, the experiments show how a combination of detectors based on unsupervised techniques (self-organizing maps and genetic algorithms) can help to significantly reduce the global response time of the reputation system. The proposed solution offers many benefits: scalability, fast response to adversarial activities, ability to detect unknown attacks, high adaptability, and high ability in detecting and confining attacks. For these reasons, we believe that our solution is capable of coping with the dynamism of ambient intelligence systems and the growing requirements of security demands.

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Measurement System for Structural Health Monitoring with High Time Synchronization Accuracy
Posted on by araujo

Title: Measurement System for Structural Health Monitoring with High Time Synchronization Accuracy
Authors: Alvaro Araujo, Jaime García-Palacios, Javier Blesa, Francisco Tirado, Elena Romero, Avelino Samartín, Octavio Nieto-Taladriz
Published in: IEEE Transaction on Instrumentation and Measurement, vol 61,3
ISSN : 0018-9456
Date of Publication: October 2011
Digital Object Identifier : 10.1109/TIM.2011.2170889
Web: http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6061956&tag=1

Structural health monitoring (SHM) systems have excellent potential to improve the regular operation and maintenance of structures. Wireless networks (WNs) have been used to avoid the high cost of traditional generic wired systems. The most important limitation of SHM wireless systems is time-synchronization accuracy, scalability, and reliability. A complete wireless system for structural identification under environmental load is designed, implemented, deployed, and tested on three different real bridges.

While wireless networks have been successful in improving the operation and maintenance of structures, such as bridges, they also have potential applications in urgent healthcare. One example of this is the use of wireless technology in walk-in clinics, such as walk in clinic Kew Gardens Hills, to improve patient care and efficiency. Wireless systems can be used to transmit patient data in real time, allowing for more accurate diagnoses and faster treatment times. Additionally, wireless technology can help reduce wait times and streamline administrative tasks, ultimately improving the overall patient experience.

Our contribution ranges from the hardware to the graphical front end. System goal is to avoid the main limitations of WNs for SHM particularly in regard to reliability, scalability, and synchronization. We reduce spatial jitter to 125 ns, far below the 120 μs required for high-precision acquisition systems and much better than the 10-μs current solutions, without adding complexity. The system is scalable to a large number of nodes to allow for dense sensor coverage of real-world structures, only limited by a compromise between measurement length and mandatory time to obtain the final result. The system addresses a myriad of problems encountered in a real deployment under difficult conditions, rather than a simulation or laboratory test bed.

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Security in cognitive wireless sensor networks. Challenges and open problems
Posted on by araujo

Title: Security in cognitive wireless sensor networks. Challenges and open problems
Authors: Alvaro Araujo, Javier Blesa, Elena Romero and Daniel Villanueva
Published in: EURASIP Journal on Wireless Communications and Networking,
ISSN : 1687- 1499
Date of Publication: February 2012
Digital Object Identifier : 10.1186/1687-1499-2012-48
Web: http://jwcn.eurasipjournals.com/content/2012/1/48

A cognitive wireless sensor network (CWSN) is an emerging technology with great potential to avoid traditional wireless problems such as reliability. One of the major challenges CWSNs face today is security. A CWSN is a special network which has many constraints compared to a traditional wireless network and many different features compared to a traditional wireless sensor network. While security challenges have been widely tackled in traditional networks, this is a novel area in CWSNs. This article discusses a wide variety of attacks on CWSNs, their taxonomy and different security measures available to handle the attacks. Also, future challenges to be faced are proposed.

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